Today, computers of various kinds have reached nearly every corner of people's lives. Computer-based technology is found in cars, televisions, telephones and even watches. With computers becoming increasingly portable, powerful, and affordable, the technology has made mobile computing a more common occurrence. As a result, more microprocessor-based computing units incorporated in various compact data entry devices have been developed.
In office environments, input to electronic data entry devices, such as personal computers, through a known QWERTY keyboard is a common occurrence. However, QWERTY keyboards are not well suited for many non-office environments or mobile use cases, since they are too large in size and require additional support to free both hands for operation.
Several alternative input methods for mobile applications have been proposed. For instance, the use of mini-keyboards have been proposed, some of which can even be folded to reduce physical size and, thus, increase portability. These mini-keyboards, however, can be inefficient and are difficult to use in many typing scenarios as the keys are often quite tiny and are tightly packed together.
The use of different keyboard layouts to reduce keyboard size has also been considered. One keyboard having as few as twelve keys has been suggested with the keys representing up to 144 characters/functions using combinations of multiple keystrokes. Alternative attempts include different layouts to fit the most frequently used keys into portable devices such as wireless mobile telephones. However, such unconventional keyboards are often difficult to learn and use. Since most people first learn to type on the QWERTY or telephone-style keyboards, their instincts tend to favor their initial training, making it difficult for them to re-learn something which deviates drastically from such initial training.
Voice recognition and handwriting recognition approaches have attempted to provide alternatives to conventional data entry in certain applications. Handwriting input approaches are often substantially slower than conventional typing, while voice input approaches still face many challenges due to background noise and other factors. In addition, the use of voice recognition systems in many situations can be disturbing to the public and also often lacks privacy.
One type of input device known as a “virtual keyboard” operates by projecting a laser image of a full-size QWERTY keyboard layout on a flat surface and also allows users to type on it. Such devices require a separate support surface and also take up considerable space during operation as a traditional full-size keyboard is displayed requiring both hands of a user to efficiently type data into the device. Furthermore, the laser projector requires relatively high power consumption. Thus, such virtual keyboards are not always well suited for the mobile environment.